steam bending plywood
Does anyone know if it is possible to steam bend 9mm bs1088 Okoume to
an 8 inch radius? Thanks! Kevin |
steam bending plywood
|
steam bending plywood
I do not believe you will get that tight a radius even with major
steaming. A more radical (and dangerous) way that would work at even tighter radiuses is to soak the wood in anhydrous ammonia. You can do some pretty amazing stuff with ammonia bending but I would not recommend it. :-) Much safer and easier to use 3 pieces of 3 mm and laminate them together after bending. Kevin wrote: Does anyone know if it is possible to steam bend 9mm bs1088 Okoume to an 8 inch radius? Thanks! Kevin -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
steam bending plywood
Ok next question...
how about steam bending 5 mm okoume to a 4 inch radius? I am debating wether to purchase the 3 mm ply and do three layers as mentioned in the previous post or to try to bend the 5mm and use two laminations. Or should I just look at using "wacky wood" or "flexy ply"? How strong are the flexible plys if used in a stitch and glue situation with the outside glassed and epoxied and the inside epoxied? Thanks, Kevin |
steam bending plywood
Probably worse. The thickness to radius ratio is even lower than 9mm to
8". Okoume is not the best steam bending wood in the world and 5 mm BS1088 has 5 plys which makes it stiffer. 3mm is only 3 ply which makes it a good bit more flexable but I am not even sure 3 mm will bend to 4". When I need to bend under about a 4" radius for fiddle rails and cabinet edges I steam up some 1/6" veneers and laminate them up from scratch. When you are getting that tight it is also necessary to use steel strapping or a well fit caul to keep the outer fibers from splitting. Kevin wrote: Ok next question... how about steam bending 5 mm okoume to a 4 inch radius? I am debating wether to purchase the 3 mm ply and do three layers as mentioned in the previous post or to try to bend the 5mm and use two laminations. Or should I just look at using "wacky wood" or "flexy ply"? How strong are the flexible plys if used in a stitch and glue situation with the outside glassed and epoxied and the inside epoxied? Thanks, Kevin -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
steam bending plywood
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steam bending plywood
I am building a 15" skiff... stitch and glue style. 3/4 merainti
bottom, 9mm okoume sides. I want to do a rounded or fantail transom. I have scarfed the sides where I am going to attach the transom, and will scarf the pieces to be bent prior to bending. The bent pieces will be part of a conic section with a 4" bottom radius and a 12" to radius. If I remember correctly the my template for the pieces to be bent is 22" tall and 26" wide at the widest point. The exterior of the sides are alread coated with 6 oz triaxle glass and the interior with 3 coats of epoxy. I will glues the scarf joint and then glass the exterior and epoxy the interior of the fantail. Thanks, Kevin Nope, I don't think the 5mm would go either. The three layers of three MM might go. As far as the other types of wood you mentioned, why don't you tell us what you are building and what it will be used for, we might be able to provide more info. Scotty |
steam bending plywood
I don't understand how there can be a 4" radius on a transom only 22" wide.
Could you mean 4" camber? Given the width of the transom and the camber of the arc you can calcuate the radius of a circular arc. If you look under "Boats" on my website you'll find a file of various formulae having do to with circular arcs for boatbuilding, also a BASIC program which calcualtes radius and points to plot on a circular arc for, say deck beams or cabin sides. You'll also find a file on dry bending plywood. Sorry, nothing on steam bending plywood. I was barely able to get a 2" camber in a 2.5' arched transom by steam heating lauan underlayment. There's photos of the completed boat, Dogskiff, on the website. It's not a power boat so its much lighter construction than your 15' skiff with a 3/4" bottom. There might be another confusing word below. The angle where things are attached to a hull is usually called "bevel" as in stem, frame, and transom bevels. The word "scarf" is used to describe the joining of two pieces of wood. The angle of the scarf is it's bevel. Kevin ) writes: I am building a 15" skiff... stitch and glue style. 3/4 merainti bottom, 9mm okoume sides. I want to do a rounded or fantail transom. I have scarfed the sides where I am going to attach the transom, and will scarf the pieces to be bent prior to bending. The bent pieces will be part of a conic section with a 4" bottom radius and a 12" to radius. If I remember correctly the my template for the pieces to be bent is 22" tall and 26" wide at the widest point. The exterior of the sides are alread coated with 6 oz triaxle glass and the interior with 3 coats of epoxy. I will glues the scarf joint and then glass the exterior and epoxy the interior of the fantail. Thanks, Kevin Nope, I don't think the 5mm would go either. The three layers of three MM might go. As far as the other types of wood you mentioned, why don't you tell us what you are building and what it will be used for, we might be able to provide more info. Scotty -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-freenet email must have "notspam" in subject or it's returned |
steam bending plywood
William R. Watt ) writes:
I was barely able to get a 2" camber in a 2.5' arched transom by steam heating lauan underlayment. There's photos of the completed boat, Dogskiff, on the website. It's not a power boat so its much lighter construction than your 15' skiff with a 3/4" bottom. I just remembered that transom is two layers of 1/5" lauan underlayment laminated with plastic resin glue. Of course that's the same as bending one layer of 1'5" underlayment. If you look closely at some of the photos you might be able to see the crease in each layer of lauan underlayment because it was a bit more than it wanted to bend. The creases don't line up and the transom is fine but some people are fussy about appearances and would complain about the creases. -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-freenet email must have "notspam" in subject or it's returned |
steam bending plywood
William R. Watt ) writes:
I just remembered that transom is two layers of 1/5" lauan underlayment laminated with plastic resin glue. Of course that's the same as bending one layer of 1'5" underlayment. If you look closely at some of the photos ^^^^ and THAT should have been 1/5" I also see your transom is not 22" wide but 22" high, and 26" wide. You still can't have a 4" radius in a 26" wide transom. :) -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-freenet email must have "notspam" in subject or it's returned |
steam bending plywood
To clarify... the template (to fit over the buck that I made) is 26"
wide at its widest point.... but this includes the radii + several inches of material that goes back along the side before the scarfs to join the transom and the sides. This maximum width is at is at the 12" radius area..... at the bottom the template is substantially narrower.... The area being covered is the surface of a conic section and so the template looks like a piece of pie with the tip cut off at a radius... let me see if I can do it in ascii art _ _ _- -_ \ / \ / \ / \n/ template Kind of.... with the scarfs along the edges. The bottom will be bending around the tight 4" radius and the top around the 12" radius. Does this make more sense? Kevin |
steam bending plywood
I want the transom to look something like this when completed.
http://www.montanaboatbuilders.com/skiff.htm Jason Cajune (who builds the boats in the pictures) does masterful work... and build the transoms by steam bending and torturing layers of ply over a buck.... Kevin |
steam bending plywood
(Kevin) wrote in message . com...
I want the transom to look something like this when completed. http://www.montanaboatbuilders.com/skiff.htm Jason Cajune (who builds the boats in the pictures) does masterful work... and build the transoms by steam bending and torturing layers of ply over a buck.... Kevin Ahhhh. I get it now, cool boat! Anyway, I still think you may need to use multiple layers of 3mm. Even if you could bend the 9mm around the bottom of the "cone" you would have to leave a lot of wood to get ahold of, or use a lot of pressure which would mean making a pretty good mold and press. Another way might be to use a couple of layers of 3mm with a layer of fiberglass inbetween and on each side. You would not need to use thick glass, just want to make it a laminated core type structure. If you are worried you could go with three layers of 3mm. Scotty from SmallBoats.com |
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